Several European countries had a few primitive railroads as early as the mid-1500's. But they were used mainly to bring up wagonloads of coal or iron ore from underground mines. The mining railroads consisted of two wooden rails that extended down into the mines and across the mine floors. Men or horses pulled wagons with flanged wheels along the rails. The wagons moved more easily along the rails than they did over the rutted or muddy entrances and floors of the mines.

In the early 1700's, English coal-mining companies began building short wooden railroads to carry coal aboveground as well as underground. Horses pulled the trains of wagons along the rails. In the mid-1700's, workers began covering the wooden rails with strips of iron to make them last longer. English ironmakers also began making all-iron rails. The rails were flanged to carry wagons with ordinary wheels. By the end of the 1700's, ironmakers were producing all-iron rails without flanges. These all-iron rails carried wagons with flanged wheels.

Invention of the locomotive. Meanwhile, inventors had been developing the steam engine. During the late 1700's and early 1800's, the English inventor Richard Trevithick built the first engines capable of using high-pressure steam. He mounted one of the engines on a four-wheeled undercarriage designed to roll along a track. In 1804, Trevithick used this vehicle to pull 10 short tons (9 metric tons) of iron, 70 men, and 5 wagons along 9� miles of track. Trevithick's invention thus became the world's first successful railroad locomotive. Soon, other English inventors had also built successful locomotives.

An English locomotive builder named George Stephenson constructed the world's first public railroad, the Stockton and Darlington, which opened in 1825. The line operated between the towns of Stockton and Darlington, a distance of about 20 miles. It was the first railroad to run steam freight trains on a regular schedule. Stephenson's second railroad opened in 1830. It ran 30 miles from Liverpool to Manchester. It was the first railroad to run steam passenger trains on a regular schedule.

Stephenson also originated the idea that a country's railroads should all have a standard gauge. The gauge he selected for the railroads he built -- 4 feet 8� inches -- corresponded to the length of the axles on many horse-drawn wagons. This gauge was eventually adopted by most European railroads and by railroads in the United States and Canada.

Developments in the United States. A few horse-powered railroads began operating in the Eastern United States in the early 1800's. In 1815, an American engineer named John Stevens obtained a charter from the state of New Jersey to build a steam-powered railroad across the state. Although Stevens could not raise enough money for this project, he still wanted to apply steam locomotion to railway track. He constructed a circular track near his estate in Hoboken, New Jersey, and built a small steam-powered vehicle to run on it. In 1825, this vehicle made a successful run.

In the late 1820's, the Delaware and Hudson Canal Company of Pennsylvania decided to build a railroad. In 1829, the company ran an English-built locomotive along a section of wooden track. This locomotive, called the Stourbridge Lion, became the first full-sized locomotive to run on a track in North America.

In 1830, the Baltimore and Ohio Railroad began service over 13 miles of track between Baltimore and Ellicott's Mills (now Ellicott City). The railroad's first cars were powered by horses. These horse-powered cars were the first railroad cars in the United States to carry passengers. The Baltimore and Ohio also experimented with a car equipped with sails. In the summer of 1830, New York manufacturer Peter Cooper built the steam-powered locomotive the Tom Thumb for the Baltimore and Ohio. But it was too small for regular service. In 1831, the railroad began regular passenger service with a locomotive called the York.

Meanwhile, the West Point Foundry of New York had built a steam locomotive for the South Carolina Canal and Railroad Company. In 1830, this locomotive, called the Best Friend of Charleston, pulled a train of cars along 6 miles of track. This event marked the first run of a steam-powered train in the United States. The Best Friend began making regular runs between Charleston and Hamburg, South Carolina, in 1831. The South Carolina Canal and Railroad Company thus became the first U.S. railroad to provide regular steam-powered passenger and freight service.

The number of locomotives and railroads multiplied rapidly in the United States after 1830. Historic first runs of locomotives included those of the De Witt Clinton on the Mohawk and Hudson Railroad in New York in 1831; the John Bull on the Camden and Amboy Railroad in New Jersey in 1831; Old Ironsides on the Philadelphia, Germantown, and Norristown Railroad in Pennsylvania in 1832; and the Pontchartrain on the Pontchartrain Railway in Louisiana in 1832. By 1835, more than 200 railroad charters had been granted in 11 states, and over 1,000 miles of track had been opened.

Meanwhile, builders were developing locomotives especially suited to the Eastern United States, where roadbeds had many curves. These locomotives had an independent wheeled undercarriage called a leading truck. The leading truck was attached to the locomotive by a center pin, which allowed the truck to swivel. A truck gave a locomotive more flexibility on curves. Most of the new locomotives had a four-wheeled truck and four driving wheels. These eight-wheeled locomotives became the most common type of U.S. locomotive during the last half of the 1800's.

Canada's first steam-powered railway, the Champlain and St. Lawrence Railroad, was started in the province of Quebec. The line opened for business as a horse-powered railroad in July 1836, and began steam-powered service later that year. The railway operated between the towns of Laprairie and Saint-Jean, a distance of about 16 miles. Other small railroads began operating in Canada soon after 1836.

Expansion in the United States. Railroads were under construction in all states east of the Mississippi River by 1850. Most of the lines were concentrated in the Northeast, and many of them ran only short distances. A network of lines radiated from Boston, New York City, and Philadelphia. Railroads also linked cities in the Southeast.

Competition for trade spurred railroad construction in the East. By the early 1850's, four railroads had built rail lines that enabled them to haul freight between the Great Lakes region and the East Coast. New York's Erie Railroad opened between Piermont and Dunkirk on Lake Erie in 1851. In 1853, 10 small railroads along the Erie Canal merged to form the New York Central Railroad, which provided service between Albany and Buffalo. By 1852, the Pennsylvania Railroad and the Baltimore and Ohio had opened lines to the Ohio River, one of the most important trade routes in the country. The large railroads took over many smaller lines and so expanded rapidly.

During the 1850's, railroad lines connected Chicago with the Mississippi River, which was a major trade route. The Baltimore and Ohio reached St. Louis on the Mississippi in 1857. Both Chicago and St. Louis thrived as transportation centers.

In 1850, Congress began granting federal land to develop railroads. Government leaders thought railroads would help attract settlers to undeveloped regions of the Midwest and the South. The railroad companies kept some of the land for right of way and sold the rest to pay railroad construction costs. The first grant helped build a railroad from the Great Lakes at Chicago to the Gulf of Mexico at Mobile, Alabama. Settlers poured into the area along the route after the railroad's completion in 1856. The success of the experiment convinced Congress to continue granting federal lands for railroad development. In return, all United States railroads agreed to carry government troops and property at half the standard rates and United States mail at four-fifths the standard rates. These rates remained in effect until the mid-1940's.

The railroads continued to expand during the 1860's. They played a major role in the Civil War (1861-1865) by moving troops and supplies to battle. The South was at a disadvantage because it had far fewer railroad tracks and locomotives than the North had. After the war, iron and steel bridges were built across such major rivers as the Ohio, the Mississippi, and the Missouri.

The first transcontinental rail lines. In the early 1860's, the United States government decided to extend rail lines across the country. The proposed route roughly followed the 42nd parallel from Omaha, Nebraska, to Sacramento, California. Eastern rail lines were to be extended westward from Chicago to meet the new railroad at Omaha. Congress passed the Pacific Railroad Act in 1862. The act gave two companies responsibility for building the railroad. The Union Pacific was to start laying track westward from a point near Omaha. The Central Pacific Railroad was to lay track eastward from Sacramento. Congress granted both railroads large tracts of land and millions of dollars in government loans.

Work began on the Central Pacific track in 1863 and on the Union Pacific in 1865. The railroads faced the gigantic task of crossing the rugged Rockies and the towering Sierra Nevada. To obtain the necessary labor, the Central Pacific hired thousands of Chinese immigrants to work on the railroad. Thousands of European immigrants worked on the Union Pacific. On May 10, 1869, the tracks of the two railroads finally met at Promontory, Utah. North America became the first continent to have a rail line from coast to coast.

By the end of the 1800's, the United States had five transcontinental rail lines. The Canadian Pacific Railway (now CP Rail) completed Canada's first transcontinental line in 1885. It extended from Montreal, Quebec, to Vancouver, British Columbia. The completion of these rail lines opened vast regions of the continent to settlement and trade.